


A Steady Warmth

by kiyala



Category: Haikyuu!!
Genre: Cryptozoology, Established Relationship, Fluff, Grinding, Hand Jobs, M/M, Paranormal, Shotgunning, Smoking, Werewolves
Language: English
Status: Completed
Published: 2015-11-05
Updated: 2015-11-05
Packaged: 2018-04-30 04:29:29
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,655
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5150276
Author URL: https://archiveofourown.org/users/kiyala/pseuds/kiyala
Summary: <blockquote class="userstuff">
              <p>Oikawa and Iwaizumi are cryptozoologists and partners in every sense of the word.</p>
            </blockquote>





	A Steady Warmth

**Author's Note:**

> This started off as a fic inspired by [this gorgeous piece of art](http://faiyuuhi.tumblr.com/post/132512253427/hes-so-good-for-my-heart) by [fai](http://faiyuuhi.tumblr.com/). Like most things I write, it got out of hand really quickly.

"I knew we'd be running late," Iwaizumi grumbles as he finds a parking space on the street. He reverses into it with a tight, precise turn. Oikawa wishes that he wouldn't make such mundane things seem so hot. "We have a schedule for a reason, you know."

"Relax," Oikawa replies, wetting his lips as Iwaizumi turns the car off and gets out. Oikawa is slow to get out of the passenger seat, carefully carrying the cake box that's been sitting in his lap for the entire trip. He cracks the lid open to check on it, smiling when he finds it still in one piece. "It was important to pick the right flavour, you know. It was definitely worth the time we spent."

"I knew what flavour you were going to pick the moment we walked into the bakery," Iwaizumi says. "I even _told you_ as much. And yet, you still spent a good fifteen minutes looking at every single other cake and asking questions about them all, before going for the one I knew you'd end up getting."

"But that's just because you know me far too well, Iwa-chan. Besides, there's going to be a full moon at the end of this week. You don't have to rush. Mad Dog-chan won't really mind if we're running a little late."

"What's that supposed to mean?" Iwaizumi asks with a frown.

Oikawa simply smiles in reply, leading the way into the apartment complex. They walk up the stairs together, to the second floor, stopping in front of apartment twenty two. Oikawa knocks on the door and waits, drumming his fingers against the side of the cake box. Iwaizumi stands beside him, close enough that their shoulders brush against each other. There's no answer, and Oikawa frowns lightly.

"Maybe they're not home? They might have forgotten we were coming."

Iwaizumi takes a deep breath. "No, they're home." 

"Oh?" Oikawa smiles. "Iwa-chan, did you use your doggie senses— _oww_."

"It's just a sharp sense of smell," Iwaizumi mutters, shaking his hand off. "It doesn't need a stupid nickname."

"Everything needs a stupid nickname," Oikawa says with conviction. "Well, if they're home, we're probably interrupting their alone time, so—"

"We'll come back later?" Iwaizumi suggests, just as Oikawa says, "I'll knock louder."

Iwaizumi sighs as Oikawa does just that. "You know, if someone else did that to you, there'd be hell to pay."

"Just as well that everybody knows better, then," Oikawa smiles, raising his fist to knock again. 

The door opens this time, and Yahaba's smiling at them brightly, a light bruise forming across his cheek. "Oikawa! Iwaizumi! Come in!"

He opens the door wider, and Oikawa catches a glimpse of his knuckles, bruised and bloody. Kyoutani's lying on the floor of the lounge room, limbs sprawled out, bleeding from his mouth.

"Did you kill him?" Oikawa asks, gingerly nudging Kyoutani's side with his foot. He yelps as Kyoutani grabs it, flailing out and grabbing a fistful of Iwaizumi's shirt for comfort, hugging the cake box to his chest. 

"He's fine," Yahaba replies. "Just a little worked up, that's all. What's in the box?"

"I'll show you once Mad Dog-chan lets go of my leg," Oikawa says, no to avail.

Iwaizumi raises an eyebrow, looking down. "Kyoutani."

That's all it takes. Kyoutani lets go of Oikawa and sits up, wiping his mouth with the back of his hand. He meets Iwaizumi's gaze for a moment, then looks away.

"Kentarou, can you carry these mugs for me?" Yahaba calls from the kitchen, and Kyoutani gets to his feet, slinking off to help. 

"Unfair," Oikawa mutters. "Why doesn't he listen to _me_ like that? Is it because he sees you as his alpha?"

"I'm not an alpha," Iwaizumi replies, shaking his head. "I can't be an alpha, Asskawa, I'm only part werewolf. A very small part."

Iwaizumi's great-grandfather was a werewolf, and passed away long before Iwaizumi was born. The only things Iwaizumi knows about being a werewolf are the bits and pieces that have been passed down from his maternal grandfather, to his mother, to him. Still, Oikawa's noticed the way that Kyoutani respects him. Even if it isn't an alpha thing, Oikawa suspects that it has at least a little to do with the fact that Kyoutani's never managed to beat Iwaizumi at anything. 

Yahaba leads the way back into the room, carrying two steaming mugs of tea, with Kyoutani on his heels with the other two. Placing all four of them on the table, Yahaba smiles brightly. "So, what's the box for?"

"It's a cake!" Oikawa announces, opening it with a flourish. "It's for you, Mad Dog-chan. To mark that it's been three months—three whole months!—since the last time you snapped at a human in public! We can stop visiting you every single week to check in with you now, isn't that exciting?"

Iwaizumi nods. "Good work, Kyoutani."

"So, the cake I got for you is chocolate," Oikawa says. "I hope that's not a problem for you, considering that chocolate isn't good for dogs?"

Kyoutani snarls. "I'll reset the count from three months back to _zero days_ since I last snapped at a human, if I have to." 

"You'll have to see me every week again, then," Oikawa replies. "If you didn't want me to leave you, Mad Dog-chan, you should have just said so."

"Stop that," Iwaizumi and Yahaba chorus, whacking Oikawa and Kyoutani on the back of their heads, respectively. 

"Enough," Iwaizumi says, his voice low and not quite threatening, but obviously displeased. 

"I'll go cut up the cake for us," OIkawa says, instead of apologising. 

"I'll help," Yahaba volunteers, patting Kyoutani's shoulder before walking to the kitchen.

Oikawa unboxes the cake, cutting it up as Yahaba takes the plates out. He looks over at Yahaba, taking in his bruises, until Yahaba's cheeks colour and he looks away. 

"It's always the week leading up to the full moon, huh?" he asks casually and Yahaba turns even redder. 

"Does Iwaizumi—?" Yahaba begins, before he turns away. "No. I'm sorry. That's none of my business."

"He's not enough of a wolf," Oikawa replies, shaking his head. "Which is a bit of a shame, maybe. It would be interesting to see him get all worked up."

"It's annoying," Yahaba says quietly. 

"That," Oikawa says, deliberately licking his lip in the same spot where Yahaba's has been bitten, "doesn't look very annoying."

" _Oikawa_ ," Yahaba protests, hiding his face in his hands.

"How are you so shy and sweet," Oikawa wonders aloud, putting cake slices onto the plates Yahaba's laid out, "while also being able to handle Mad Dog-chan so well? You're terrifying when you're angry, but even then, you're sweet about it. Do you remember when we lived in Miyagi, and you'd want to drown anyone who pissed you off?"

"The city is a better place for a nymph," Yahaba smiles. "Fewer bodies of water to drown people in. It curbs the temptation."

"See?" Oikawa reaches out to pinch Yahaba's cheek. "You're cute even when you're talking about murder."

They go back out to the lounge room, sitting around the coffee table. Kyoutani likes the cake, just as Oikawa knew he would, and this is still technically a work visit. It's part of Oikawa and Iwaizumi's jobs to liaise with the city's resident cryptids, to help them find a balance between living their lives and sharing the city with the human population, most of which is largely unaware of their existence. But it's the last visit and they're all old friends anyway, from long back, when they still lived in Miyagi and most of the cryptids Oikawa knew were the youkai who lived in the quieter areas. It doesn't matter if this is mostly a social visit. Considering how far they've all come, he figures that they deserve it. Besides, it's been a long day and Oikawa could do with some relaxation time.

Iwaizumi's phone buzzes with a text and he makes a low sound of concern, passing it over to Oikawa. "I think we need to go."

Oikawa frowns down at the screen, which is open to a text from Kindaichi. It simply reads: _HELP I'M AT THE OFFICE I MADE A TERRIBLE MISTAKE_.

"Oh, Kindaichi," Oikawa sighs. He smiles at Yahaba and Kyoutani. "Well, we might have to visit again later. Iwa-chan and I need to go attend to our baby."

"Stop calling him that," Iwaizumi mutters as he gets to his feet. "He's—a toddler, at the very least. Yahaba, Kyoutani, we'll see you again soon, okay?"

It doesn't occur to Oikawa until they're back in the car, but then he turns to Iwaizumi with wide eyes. "You didn't deny the fact that Kindaichi is our son."

"Well, you treat him like it," Iwaizumi sighs. "So do I. Maybe."

"I knew you'd come around," Oikawa beams. "I always knew you'd make a good father." 

" _Tooru_." Iwaizumi actually takes his eyes off the road to stare at Oikawa, his cheeks burning red, and nearly rear ends another car because of it. He turns back to his wheel, rubbing a hand across his mouth. "Holy shit."

"I didn't—" Oikawa begins, but stops, because he _did_ mean it. "I didn't meant to say it like that. I don't mean anything by it, you know that. It's just. It's been a long day. Ignore me."

"Like hell I'm going to ignore that," Iwaizumi mutters, and Oikawa is relieved to note that he doesn't sound annoyed, or scared. If anything, he sounds thoughtful. "We'll talk about it. Maybe not right now, but…"

"Yeah," Oikawa agrees, feeling only a little uneasy about it. Things could be worse. Besides, they have Kindaichi to take care of right now, and whatever mess he's gotten himself into.

Said mess, they discover as they return to the office, is an entire nest of pixies that Kindaichi has somehow managed to knock over while cleaning. They'd been nesting in an old archiving box that nobody's bothered to touch for years and now, Kindaichi's being swarmed by the tiny, glowing creatures, and he's slowly but surely being covered in glittering pixie dust. It's probably going to take the next month to wash it all out of his hair. 

Oikawa laughs so hard that he doubles over, having to lean against the wall for support. There are tears in his eyes and he can't breathe. 

"What a shitty dad," Iwaizumi mutters, and that only makes Oikawa laugh even harder. 

Kindaichi is yelling with terror, and Iwaizumi steps forward, picking up the box the pixies had been nesting in. He whistles at them, and Oikawa knows from experience that he can hold a tune decently enough. The pixies stop swarming Kindaichi as they listen, and Iwaizumi holds the box out, shaking it enticingly. 

"Kindaichi's sorry, but you're going to have to stop being mad at him. It was an accident," Iwaizumi tells them. "Come on—look at the nest you've built in here. You want to keep it, right?" 

The pixies confer with each other, before returning to their nest. Iwaizumi puts the box down on the nearest table, not putting the lid back on, and looks at OIkawa, who is now sitting on the floor, leaning back against the wall.

"This is your fault, somehow," Iwaizumi says, pointing at him. "You brought the pixies in here, didn't you?"

Oikawa smiles innocently. Unfortunately for him, Iwaizumi can see right through it. Iwaizumi sighs heavily, then goes to pat Kindaichi on the back.

"Hey, you okay? You look pretty shaken up there, you know."

"I'll be fine," Kindaichi smiles. "Thank you. Sorry. I should know how to handle pixies. I mean. I _do_ know. I panicked."

"You'll remember next time, won't you?" Oikawa says, as Iwaizumi helps him to his feet. "As long as you learn from the experience, it's okay, right?" 

Kindaichi's smile grows even wider. "Yeah, you're right. Thanks. Sorry to call you back to the office. I'll finish cleaning and close up by myself. You can go home. You've both worked a really long day, haven't you?"

They've been working since dawn, and it's roughly eight o'clock at night now. Oikawa feels tired now that he's thinking about it, and he can see the exhaustion creeping into Iwaizumi's posture as well.

"We'll be off, then," Oikawa says, placing his hand on Iwaizumi's back and guiding him towards the door. "Be careful while you're cleaning, okay? If you need help…"

"Call someone else," Iwaizumi finishes, but his tone is so gentle that it doesn't sound like an admonishment at all, and Kindaichi doesn't take it as such either. 

The drive home is a fairly short one, and they're both silent in the car, exhausted from their long day, not sure how to approach the heavy topic hanging over them. They'll need to address it eventually, Oikawa knows that. They don't really talk about their future much and Oikawa honestly doesn't know what to say anyway. He's always assumed that they'd be together, whatever they did, and he's been right about that so far. He's been living with Iwaizumi for years now, and their lives are so entwined by this point that he can't even imagine what it would be like to be without him. 

They don't even bother to turn the lights on as they go inside. Light filtering through the windows from the street is always bright anyway and on top of having a sharp sense of smell, Iwaizumi has good night vision, so Oikawa's learned to adjust. They make their way to the bedroom and Oikawa sighs heavily, sprawling out on their bed. Iwaizumi huffs fondly, sitting down on the chair beside his desk. Oikawa shuts his eyes, listening to Iwaizumi grope around for his lighter and pack of cigarettes. 

"It's been one of _those_ days, has it?" Oikawa asks.

"We started our day with a harpy who refused to talk to us at any other time of the day except _during sunrise_. We've had to deal with a bogeyman, a kitsune who kept talking in circles, a banshee, and visiting Kyoutani was meant to be a relaxing thing. Which didn't work out too well. And then you said… what you did…" 

"Yeah," Oikawa hums, and a silence falls over them, not entirely as comfortable as it usually is between them. Taking a deep breath, Oikawa props himself up on his elbows, looking at the shadowy figure of Iwaizumi. "You know I meant it though, don't you? I'm not asking for anything, I'm just stating facts here. The only thing I'm really asking for is to keep spending my life with you, the way we are now. I like that we're partners in every sense of the word. I want to keep doing this. Even when things change, we find a way to get around it, we adjust to it, to each other. I like that. I love you. You know that too."

Iwaizumi huffs again, and the worry is gone from his tone as he says, "Yeah. Love you too."

He flicks his lighter on and the flame illuminates his face, cigarette held between his lips, mouth curved into a gentle smile that Oikawa wants to trace with his thumb, with his lips. 

"You're smiling," Oikawa murmurs, and finds that he's smiling too.

Iwaizumi exhales smoke, the room going a little darker as he puts his lighter's flame out. "I'm allowed to be happy."

"Of course you are." Oikawa rests his head back on the mattress. "I'm happy that you're happy, but Iwa-chan, you're meant to save the cigarette for _after_ sex, aren't you?"

"…That was awful."

" _I'm_ awful," Oikawa replies, smiling as he hears Iwaizumi get up, crossing the short distance to the bed. The mattress sinks a little as Iwaizumi rests a knee against the edge of the bed. Oikawa runs his foot along the inside of Iwaizumi's thigh, looking up at him.

Iwaizumi shrugs out of his vest, letting in fall to the floor, and reaches down with his free hand, grabbing Oikawa by the ankle. He exhales smoke, stroking his thumb along the dip of Oikawa's ankle. "You're ridiculous. Do I tell you that often enough? I love you."

"You should say that last bit more often," Oikawa says, raising his eyebrows. Iwaizumi moves further up the bed, running his hand along Oikawa's leg, then across his stomach and up his chest. "I like hearing it."

"I know you do," Iwaizumi murmurs, taking hold of Oikawa's chin. "Come here."

Oikawa sits up as Iwaizumi takes a drag of his cigarette, opening his mouth. Iwaizumi lines their lips up, exhaling gently. Oikawa makes a needy sound at the back of his throat, taking the cigarette from Iwaizumi's fingers. 

There's an ash tray on their bedside table, for these exact situations. Oikawa reaches for it, putting it down beside them on the bed and tapping the cigarette against it. He raises it to his lips, taking a long drag. 

"That's my cigarette," Iwaizumi growls, but he's smiling, leaning in, inhaling as Oikawa exhales. They're the perfect push and pull against each other, fitting together as if they're made for each other. Sometimes, Oikawa is certain that they _are_ , that they were made to balance each other out, to be together like this, because it makes perfect sense. 

The cigarette slowly dwindles between their hands and mouths, until it's gone altogether, the butt left in the ash tray, placed back on the table. This time, when their lips come together, they don't part for a long time. Iwaizumi pushes Oikawa down against the mattress, crawling on top of him without breaking their kiss. They're both hard, but they're also worn out, their movements slow. Iwaizumi gets their pants down to their knees and they wordlessly decide that this is enough. The tip of Iwaizumi's nose skims across the sensitive skin of Oikawa's neck, leaving goosebumps behind. Oikawa shudders pleasantly, fingers digging into Iwaizumi's shoulders. 

"You're smelling me, aren't you?" Oikawa asks, his tone light and teasing to hide just how much he loves the thought of it. "I probably just smell like cigarette smoke."

"And pixie dust," Iwaizumi replies. He breathes deeper, not even trying to be subtle about it now. "A bit like cake. But I can smell you under all of that. You smell good."

Oikawa feels his cheeks growing warm and he turns his face into Iwaizumi's hair, kissing it. "You say that every time. You're biased."

"Maybe," Iwaizumi allows, pulling back to look Oikawa in the eyes. "But I still mean it, every time."

They kiss messily as Iwaizumi wraps his fingers around both their cocks, stroking slowly. Oikawa gasps, hips jerking, fingers curling against the nape of Iwaizumi's neck, right where he likes it best, scratching lightly with his blunt fingernails. Iwaizumi lets out a low, pleased hum and strokes harder. 

Sex with Iwaizumi is easy, because they know each other's bodies so well. They've fumbled their way through the awkward stages together, learning each other's bodies while learning themselves, and now it's difficult to tell where one ends and the other begins. Oikawa knows every part of Iwaizumi's body, has mapped it all with his lips and teeth and tongue, committing it to memory. He can shut his eyes and recall any given part of Iwaizumi's body, whether he likes being touched there, how he likes being touched, all just as easily as he remembers his friends' favourite foods, or how best to approach the different cryptids he works with. 

Iwaizumi knows him just as well, knowing exactly how to reduce Oikawa to a trembling, pleading mess. He does it often; he likes watching Oikawa lose his composure, likes stripping away every last thing that Oikawa can hide behind until he's laid out bare, honest and open and _desperate_ , always so desperate for anything and everything Iwaizumi has to give him. 

"Mm, you're going to come," Iwaizumi murmurs, not a question because he doesn't need to ask. He knows by Oikawa's sharp gasps, by the way his hips jerk. "Let me hear you."

Oikawa does, moaning right into Iwaizumi's ear as he's stroked through his orgasm. He reverses their positions, so he's sitting on top of Iwaizumi, grinding against him. Oikawa doesn't finger himself, not right now when they're both too tired for anything more, but spreads himself open, teasing Iwaizumi as he positions himself against the very head of Iwaizumi's cock, rocking his hips slowly. 

"Tooru—fuck—" Iwaizumi's voice is shaky, his grip firm enough on Oikawa's hips to leave bruises behind. "I'm gonna—"

"Yeah," Oikawa pants, smiling. "Come on."

Iwaizumi arches, coming all over Oikawa's thighs. Oikawa hums happily, sitting back and pushing his thighs together, enjoying how messy he feels. Iwaizumi smiles, stroking his hands along Oikawa's thighs, unbothered by the mess. 

"I'm going to clean up," Oikawa murmurs, once Iwaizumi's strokes slow, his eyelids growing heavy. "I'll be back." 

"Mm," Iwaizumi replies. "I'll be here."

Oikawa shuts the bathroom door before turning the light on, so it doesn't disturb Iwaizumi. He squints against the sudden brightness, grabbing a towel and wetting it, wiping himself clean before carrying it to the bedroom. Iwaizumi is sleepy but shifts obligingly, letting Oikawa clean him off too. Oikawa dumps the towel in their laundry hamper, deciding they can deal with it later. Iwaizumi is most of the way asleep now and makes sleepy, content sounds as Oikawa settles down beside him. It's cuter than Iwaizumi has any right to be, and Oikawa can't get the smile off his face again. 

"Love you, Hajime." 

Mumbling indistinctly in reply, Iwaizumi rolls onto his side, wrapping an arm around Oikawa's waist. Oikawa exhales slowly, resting their heads together, relaxing immediately. Iwaizumi has always been home to him, has always made Oikawa feel safe. That hasn't changed once in all the years they've known each other. Oikawa knows that it won't.


End file.
